Timer with adjustable cam-operated switch



Aug. 31, 1965 R. L. BERG 3,204,050

TIMER WITH ADJUSTABLE CAMOPERATED SWITCH Filed Nov. 19, 1962 INVENTOR. R ALPH L. BERe ATTORNEY United States Patent 3,204,05 TIMER WITH ADJUSTABLE CAM-OPERATED SWITCH Ralph L. Berg, Crystal Lake, Ill., assignor to Controls Company of America, Melrose Park, Ill., a corporation of Delaware Filed Nov. 19, 1962, Ser. No. 238,691 3 Claims. (Cl. 20038) This invention relates to timers of the types in which a switch is operated by an actuating mechanism having two cams which are selectively movable relative to each other in order to vary the switch actuation and which open as well as close the switch in response to a drop on the cam.

The object of this invention is to provide a timer of the type described and having versatility and a wide range of adjustment.

Other objects and advantages will be pointed out in or be apparent from the specification and claims, as will obvious modification of the embodiment shown in the drawings in which:

FIG. 1 is a front elevation of the timer with the switch in an open position;

FIG. 2 is a fragmentary side view of the timer when the switch is in the open position;

FIG. 3 is a fragmentary bottom view of the timer shown in FIG. 1;

FIG. 4 is a fragmentary front view of the timer showing the position of the actuating mechanism at the instant of closing of the switch; and

FIG. 5 is a fragmentary front view of the timer with the switch in a closed position shortly before it is opened and showing the latching means superimposed in broken lines to illustrate the position to which the latching means is moved as the switch blades are moved upwardly by the rise portion of the cam which is shown to approach the blades.

Referring to the drawings, switch and actuating mechanism 12 are mounted on motor housing 14 with the upper blade 16 biased downwardly towards lower blade 18 to close the switch by establishing contact between two contacts 24 and 26. Housing 14 contains a motor and reduction gearing which drive shaft 28 in a clockwise direction (FIGS. 1, 4 and 5). Cam 30 is fixed to shaft 28 while front cam 32 is rotatably mounted thereon to permit it to be selectively moved between a plurality of angular positions in respect to cam 30. The position of front cam 32 relative to cam 30 may be easily changed by loosening nut 36 to relieve the pressure on teeth 34, rotating cam 32 to the desired position, and thereafter tightening the nut to again engage teeth 34. However, it should be apparent to those skilled in the art, that earn 32 could also be spring biased against and frictionally engage the cam 30. Cam 32 could also be provided with a tab by means of which cam 32 could be moved relative to cam 30.

With actuating mechanism 12 in the position shown in FIG. 1, switch 10 is open and has its upper blade 16 held out of contact with lower blade 18 by shoulder 38 of lever 40. The lever and its shoulder comprise latching means 41. The lever is pivoted on pin 46 and is biased in a counter-clockwise direction (FIG. 1) against stop 42 by hairspring 47. Stop 42 projects from follower 44 which is also pivoted on pin 46. Follower 44 has a forwardly projecting follower end 50 and is biased in a clockwise direction (FIG. 1) by spring 48 to thereby cause end 50 to be biased against and ride on the dwell surface 51 of cam 30.

As the cams rotate (from the position shown in FIG. 1) in the direction indicated by the arrows, notch 52 forming the drop surface 53 moves under the end 50 and the spring 48 causes the end to drop into the notch thereby causing the follower 44 to pivot to the position shown in FIG. 4. As illustrated, such pivotal motion also moves lever 40 and shoulder 38 to the right to allow blade 16 to snap into contact with blade 18 and thereby close the switch 10.

Upon further rotation of the cams (from the position shown in FIG. 4) follower end is forced out of the notch by the rise surface 55 and the follower 44 pivots back to its original position (FIG. 5). Since blade 16 has snapped downwardly to close switch 10, shoulder 38 will pivot back to a position above blade 16 as shown in FIG. 5. During this step the timer switch remains closed. Upon further rotation of the cams (from the position shown in FIG, 5), the rise portion 57 0f finger 54 of cam 32 engages the downwardly bent follower end 56 of blade 18 and forces both blades upwardly. During such upward motion the switch remains closed. As upper blade 16 encounters the underside of shoulder 38 it forces lever 40 to pivot outwardly around pin 46 and against the bias of spring 47 to the position shown in broken lines in FIG. 5. As the upward motion of both blades continues blade 16 clears shoulder 38 and permits lever 40 to pivot back to its position underneath blade 16. Thereafter the drop surface 59 of finger 54 moves underneath the tip of the follower end 56 of the lower blade and permits the blade to drop back to its original position. However, since shoulder 38 prevents any downward motion of the upper blade, the drop of blade 18 will open the switch and the follower and the switch blades will assume the positions as illustrated in FIG. 1.

It will be appreciated that the portion of time within each cycle (one rotation of the cams) during which the timer switch is closed is only dependent upon the angular position of finger 54 in respect to notch 52 and that such angular position may be readily changed to provide any desired program. This range of adjustment is almost 360, which renders the control extremely versatile. Since the follower must be riding on the downward portion of cam 30 when the break-to-open occurs, it will be appreciated that the angular portion of cam 30 devoted to the drop and rise determines the minimum time of the timer. If the cams make one revolution in 12 hours and the angular portion is 10, then of 12 hours (20 minutes) is the minimum time.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A motor driven timer comprising:

a switch having a first and a second contact means, said first contact means being biased towards said second contact means, and said switch being closed when said first and second contact means are in contact with each other and being open when said first and second contact means are in a spaced relationship in respect to each other;

first cam means having a drop surface, a rise surface and a dwell surface;

second cam means having a drop and a rise surface,

both of said cam means being connected to the motor for rotational movement in respect to said switch;

cam follower means engaging said first cam means and including latching means which, when said switch is open, engages said first contact means and retains said first contact means in said spaced relationship in respect to said second contact means, said follower means being maintained in a position in which said latching means is capable of engaging said first contact means while said follower meahs engages said dwell surface of said first cam means, said follower means moving said latching means out of engagement with said first contact means when said follower means encounters said drop surface of said first cam and thereby causing said first contact means to move to a contacting position with said second contact means, upon encountering said rise surface of said first cam means said follower means moving said latching means to a position in which said latching means is capable of engaging said first contact means;

said rise surface of said second cam means moving said first and second contact means from one position to another position while said contact means are in said contacting position in respect to each other, said drop surface of said second cam means causing said second contact means to move back to said one position and causing said first contact means to engage said latching means to permit said first and second contact means to assume a spaced relationship in respect to each other; and

means to vary the relative angular position of said first cam means in respect to said second cam means to thereby vary the length of switch-open and switchclosed time during one revolution of said first and second cam means.

2. A motor driven timer comprising: a first and a second cam both being rotated by the motor and both having a rise and a drop surface; adjustable means to vary the relative positions of said drop surfaces in respect to each other; a first and second blade, said first blade being biased towards said second blade, and said second blade being normally positioned intermediate said first blade and said earns; a follower which in its normal position engages said first cam and which contains latching means which engages and holds said first blade against its bias and in a position in spaced relationship in respect to said second blade; said follower moving in response to the drop of said first cam and causing said latching means to release said first blade to cause it to move towards and into Contact with said second blade; said follower being moved back to said normal position in response to the rise of said first cam; said first and second blades being moved by the rise of said second cam while remaining in contact with each other to a position generally corresponding to a position at which said first blade may be engaged by said latching means said second blade moving to its normal intermediate posit-ion in response to the drop of said second cam, and said latching means engaging said first blade at this time to hold said blade against its bias in said position in spaced relationship in respect to said second blade.

3. A timer according to claim 1 wherein said latching means is comprised of a lever member, which, when said follower is in said normal position, is positioned to be able to prevent movement of said first blade towards said second blade, said lever being moved out of said position by said first blade as said first and second blades are moved by the rise of said second cam and moving back to said position before said blades respond to the drop of said second cam.

References Cited by the Examiner UNITED STATES PATENTS 2,124,045 7/38 Swensen 20038 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCI-IAEPER, Examiner. 

1. A MOTOR DRIVEN TIMER COMPRISING: A SWITCH HAVING A FIRST AND A SECOND CONTACT MEANS, SAID FIRST CONTACT MEANS BEING BIASED TOWARDS SAID SECOND CONTACT MEANS, AND SAID SWITCH BEING CLOSED WHEN SAID FIRST AND SECOND CONTACT MEANS ARE IN CONTACT WITH EACH OTHER AND BEING OPEN WHEN SAID FIRST AND SECOND CONTACT MEANS ARE IN A SPACED RELATIONSHIP IN RESPECT TO EACH OTHER; FIRST CAM MEANS HAVING A DROP SURFACE, A RISE SURFACE AND A DWELL SURFACE; SECOND CAM MEANS HAVING A DROP AND A RISE SURFACE, BOTH OF SAID CAM MEANS BEING CONNECTED TO THE MOTOR FOR ROTATIONAL MOVEMENT IN RESPECT TO SAID SWITCH; CAM FOLLOWER MEANS ENGAGING SAID FIRST CAM MEANS AND INCLUDING LATCHING MEANS WHICH, WHEN SAID SWITCH IS OPEN, ENGAGES SAID FIRST CONTACT MEANS AND RETAINS SAID FIRST CONTACT MEANS IN SAID SPACED RELATIONSHIP IN RESPECT TO SAID SECOND CONTACT MEANS, SAID FOLLOWER MEANS BEING MAINTAINED IN A POSITION IN WHICH SAID LATCHING MEANS IS CAPABLE OF ENGAGING SAID FIRST CONTACT MEANS WHILE SAID FOLLOWER MEANS ENGAGES SAID DWELL SURFACE OF SAID FIRST CAM MEANS, SAID FOLLOWER MEANS MOVING SAID LATCHING MEANS OUT OF ENGAGEMENT WITH SAID FIRST CONTACT MEANS WHEN SAID FOLLOWER MEANS ENCOUNTERS SAID DROP SURFACE OF SAID FIRST CAM AND THEREBY CAUSING SAID FIRST CONTACT MEANS TO MOVE TO A CONTACTING POSITION WITH SAID SECOND CONTACT MEANS, UPON ENCOUNTERING SAID RISE SURFACE OF SAID FIRST CAM MEANS SAID FOLLOWER MEANS MOVING SAID LATCHING MEANS TO A POSITION IN WHICH SAID LATCHING MEANS IS CAPABLE OF ENGAGING SAID FIRST CONTACT MEANS; SAID RISE SURFACE OF SAID SECOND CAM MEANS MOVING SAID FIRST AND SECOND CONTACT MEANS FROM ONE POSITION TO ANOTHER POSITION WHILE SAID CONTACT MEANS ARE IN SAID CONTACTING POSITION IN RESPECT TO EACH OTHER, SAID DROP SURFACE OF SAID SECOND CAM MEANS CAUSING SAID SECOND CONTACT MEANS TO MOVE BACK TO SAID ONE POSITION AND CAUSING SAID FIRST CONTACT MEANS TO ENGAGE SAID LATCHING MEANS TO PERMIT SAID FIRST AND SECOND CONTACT MEANS TO ASSUME A SPACED RELATIONSHIP IN RESPECT TO EACH OTHER; AND MEANS TO VARY THE RELATIVE ANGULAR POSITION OF SAID FIRST CAM MEANS IN RESPECT TO SAID SECOND CAM MEANS TO THEREBY VARY THE LENGTH OF SWITCH-OPEN AND SWITCHCLOSED TIME DURING ONE REVOLUTION OF SAID FIRST AND SECOND CAM MEANS. 